The weight limits of “actual” MTBs are also accounting for jumps and landings and other rough mistreatments. You can go over the limit by a fair amount safely as long as you don’t do those (until all the riding has shed enough of that weight). You’ll just wear parts a bit faster but parts can be replaced and upgraded.

I’d recommend for the next bike (as i’m assuming the Walmart bike doesn’t) to get something with 15mm thru axles. As the larger size and stronger build will absorb more of the strain instead of putting it on the hubs and bearings.

I’m 120kg and have no logistical or mechanical issues riding. Guessing the troubles start at 130kg. So that’s a goal.